Bag closing machine



APril 1967 s. c. RUSTAD ETAL 3,313,089

BAG CLOSING MACHINE Filed Oct. 7, 1964 14 Sheets-Sheet 1 FIG. IA

FIG. IG FIG. ID

INVENTORS STANLEY C RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN MI/ M ATTORNEY April 11, 1967 s. c. RUSTAD ETAL v 3,

BAG CLOSING MACHINE Filed Oct. 7, 1964 14 Sheets-Sheet? FIG. 2A 124 FIG. 3A

INVENTORS STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN ATTORNEY Apri! 1967 s. c. RUSTAD ETAL 3,313,089

BAG CLOSING MACHINE Filed Oct. 7, 1964 14 Sheets-Sheet (5 INVENTORS STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN ATTORNEY April 1967 s. c. RUSTAD ETAL 3,313,089-

BAG CLOSING MACHINE Filed Oct. 7, 19 64 14 Sheets-Sheet 4 PRELOAD STATION IN VENTORS' STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN ATTORNEY p 1967 s.c. RU STAD ETAL 3,313,089

BAG CLOSING MACHINE I4 Sheets-Sheet 5 Filed Oct. 7, 1964 INVENTORS STANLEY c. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON BY MARK HASTEN M fl ATTORNEY April 11, 1967 s. c. RUSTAD ETAL 3,313,089

BAG CLOSING MACHINE Filed Oct. 7, 1964 v 4 Sheets-Shet 6 INVENTOR$ STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN MI /2 4b ATTORNEY April 1967 s. c. RUSTAD ETAL 3, 3,

' BAG CLOSING MACHINE Filed Oct. '7, 1964 14 Sheets-Sheet 8 ll. IIL

BY MARK HASTEN ATTORNEY April 11, 1967 5, s D ETAL 3,313,089

BAG CLOSING MACHINE Filed 001;. 7, 1964 14 Sheets-Sheet 9 mNT HENRY E. wissMAN ROBERT D. SIVERSON MARK HASTEN ATTORNEY Ap 1967 s. c. RUSTAD ET'AL 3,

BAG CLOSING MACHINE Filed 001;. 7, 1964 14 Sheets-Sheet 10 FIG. I28 1N VEN TOR STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN ATTORNEY April 11, 1967 S. C. RUSTAD ETAL BAG CLOS ING MACHINE l4 Sheets-Sheet 11 Filed Oct. '7, 1964 IN VENTORS n D N N Nw R mm m E T mwwmfi A s bm -H A V R RE NBR v TEO SHRM B April 1967 s. c. RUSTAD EYTAL 3,313,089

BAG CLOS ING MACHINE 14 Sheets-Sheet 12 Filed 001;. 7. 1964 AIR SUPPLY INVENTORS STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN BY z a g 2 6 ATTORNEYv 'April 11, 1967 s. c. RUSTAD ETAL 3,

BAG CLOSING MACHINE Filed Oct. '7, 1964 14 SheetsSheet l5 v Ca 08 lss FIG. I70

FIG. l8b FIG. |8c

INVENTORS STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN BY M 7% ATTORNEY A ril 11, 1967 s. c. RUSTAD ETAL 3,313,089

BAG CLOSING MACHINE Filed Oct. 7, 1964 14 Sheets-Sheet 14 FIG. |9b FiG. l9c

FIG 20b FIG. 20

FIG. Zlo

' FIG. Zlb FIG. Zic

INVENTORS STANLEY C. RUSTAD HENRY E. WISSMAN ROBERT D. SIVERSON MARK HASTEN y/94 4 ATTORNEY United States Patent 3,313,089 BAG CLOSING MACHINE Stanley C. Rustad, Minneapolis, Henry E. Wissman, St.

Paul, and Robert D. Siverson and Mark Hasten, Minneapolis, Minm, assignors to General Mills, Inc., a corporation of Delaware Filed Oct. 7, 1964, Ser. No. 402,223 25 Claims. (Cl. 53-371) This invention relates to an improved machine to close filled bags.

It is a principal object of the present invention to provide a machine which will close filled paper bags in a manner that the bags are consistently folded down neatly without any substantial amount of wrinkling.

It is a further object to attain the ends of the above recited object by means of a machine which in its structure and operation is relatively simple, and will perform its intended functions reliably and effectively, and with a relatively high rate of output. In this regard, it is noted that in this machine the bags are indexed into a continuously moving conveying mechanism, and the bags are folded while moving at a constant rate of travel to the discharge end of the apparatus, the apparatus being such that possible malfunctions or irregularities in its operation are kept to a practical minimum.

It is a more particular object that the apparatus of this invention function in such a manner that with each bag being held in a neatly folded position, further closing operations (e.g. sewing, taping, gluing, or further folding the bags) can effectively be performed while the bag is being carried by the conveying mechanism of the ap' paratus.

It is a further particular object that the apparatus be so arranged that without detracting from ends of the other objects recited herein, it can easily be adjusted to accommodate bags filled to different levels.

These and other objects and features of the invention will be more readily understood and appreciated from the following detailed description of the preferred em bodiments thereof selected for purposes of illustration and shown in the accompanying drawings, in which:

FIGURES 1A through 1D show a bag of the type which is closed by the machine of the present invention, through successive stages of a complete closing operation;

FIGURES 2A and 2B, shown on separate drawings, are arranged to be viewed in side by side relationship to present a side elevational view of the entire apparatus of the present invention;

FIGURES 3A and 3B are sectional views taken on,

respectively, lines 3A3A of FIGURE 2A and lines 3B3B of FIGURE 2B; FIGURES 3A and 3B also are arranged to be viewed in side by side relationship to present a plan sectional view along the plane designated by lines 3A3A and 3B3B to show the drive mechanism of the present invention;

FIGURE 4 is a fragmentary top plan view of the infeed portion of the apparatus of the present invention,

as seen from the location indicated at 4-4 in FIG URE 2A;

FIGURE 5 is a transverse sectional view taken along line 5-5 of FIGURE 2A, this section being taken at a location to better show the fold-in mechanism of the present invention;

FIGURE 6 is a fragmentary longitudinal sectional view taken on line 6-6 of FIGURE 5, also to show the fold-in mechanism of the present invention;

FIGURE 7 is a plan sectional view taken along line 7-7 of FIGURE 6 to illustrate the drive for the fold-in mechanism of the present invention;

FIGURE 8 is a plan sectional view taken along line 8-8 of FIGURE 6 to illustrate the operation of the foldin plates of the present invention;

FIGURES 9, 10 and 11 are schematic views, taken generally in side elevation, showing the operation of a cam mechanism of the present invention in three successive stages of operation;

FIGURES 12A and 12B are fragmentary plan sectional views, each being taken along line 12--12 of FIG- URE 2B, and illustrating successive stages of operation of the outfeed portion of the present invention;

FIGURE 13 is a stripped-down side elevational view, illustrating those portions of the apparatus of the present invention which are vertically adjustable to accommodate bags filled to different heights;

FIGURE 14 is a plan view of that portion of the apparatus shown in FIGURE 13;

FIGURE 15 is a diagrammatic sketch of the actuating and interlock mechanism for the infeed pushers of the present invention, and

FIGURES 16A, B, and C through 21A, B, and C are a group of diagrammatic drawings showing successive stages of operation as a bag is being folded by the apparatus of the present invention.

It is believed a clearer explanation of the present invention will be achieved if the detailed description thereof is preceded by a brief discussion of the problems encountered in closing a filled paper bag and of the general approach taken in the present invention to solve such problems.

By referring toFIGURES lA-lD, wherein is shown the type of bag which is folded down by the apparatus of the present invention, it can be seen that the make-up of the bag and the configuration to which it is folded are both conventional. Such bags come prefolded in the manner shown in FIGURE 1A. In the overall packaging operation, each bag is opened to assume the general configuration of a rectangular prism, and a predetermined portion of the product to be packaged is then poured into the bag up to a certain level (as shown in FIGURE 1B), after which the top portion of the bag is folded in the manner shown in FIGURE 10. With the bag in the folded configuration of FIGURE 1C, further operations such as cutting off the top of the bag, sewing and/ or taping the bag can be performed. Finally, the bag can, if desired, be folded down and over so as to be adjacent the top level of the contained product (as shown in FIG- URE 1D).

The operation of. folding the bag from the open configuration of FIGURE 1B to the position of FIGURE 1C is especially critical in obtaining a neat and proper closure, and it is with this portion of the bag closing operation that the present invention is especially concerned. However, as indicated previously, it is also of significance in this invention that this folding operation be performed in such a way that subsequent operations, such as cutting off the top of the bag, sewing, taping, gluing, folding down, etc., can be conveniently and properly performed.

Probably the main source of difficulty in folding the bag so as to get a neat closure without any substantial wrinkling is that when a granular product is poured into the bag, the sides of the bag will bulge out so that a section taken horizontally through the bag at the middle or top portion thereof will have a somewhat oval or rounded configuration. The diificulties which this bulging creates are best understood by examining FIGURE 1B which illustrates a bag having a configuration of a perfect rectangular prism (i.e. without any such bulging) and showing in broken lines the fold lines along which the bag would be folded in an ideal situation to obtain a perfectly neat closure. This bag is designed generally by numeral 10, and the side and end panels thereof are designated 12 and 14, respectively. The level to which the product 16 is filled in the bag is designated 16', and the portions of panels 12 and 14 which extend above the product level 16' (these being the closure portion of the 'bag 10), are accordingly designated 12 and 14', respectively, and collectively are designated 10".

Letter designations for the points at which the various fold lines intersect have been applied only on the front and side panel closure portions 12' and 14' which are wholly exposed in FIGURE 1B. In the following description, when such letter designations are used in defining various lines and parts of the panel closure portions 12' and 14', the line or part so defined by certain letters on one panel portion 12' or 14 is also intended to refer to the corresponding line or part on the opposite panel closure portion 12 or 14'.

The hinge lines, a, b and b, 0, along which the sides 12 and end panels 14 are folded in, coincide with the product level 16. Each triangular portion 1), e, c is folded flat against the product 16, and is overlayed by triangular portions b, e, f and c, e, d; the rectangular portions adjacent the hinge line a, b (one of which is defined by points a, b, f, g) overlie these triangular portions, and also lie adjacent the top level 16' of the product 16. The rectangular portions g, f, i, h of panel 12 and its corresponding rectangular portion from the other side panel 12 are caused to be moved in adjacent one another so as to be upstanding from the longitudinal center line of the bag closure, and the uppermost rectangular portions (one of which is seen to be defined by points f, d, k, i of the end panels 14) are contained between the side panel rectangles g, f, i, h, and are formed with a reentrant fold, as along line e,

However, when the open bag 10, is filled so that the product 16 causes the panels 12 and 14 of the bag 10 to bulge, it is apparent that the straight-lined geometric figures defined by the above recited fold lines will suffer some distortion. Notably, the rectangle a, b, g of each side panel 12 will curve outwardly, and when it is attempted to fold in'each rectangle a, b, j, g along its hinge line a, b, wrinkles will form, especially near the end portions of the rectangle where the curvature is greatest.

Recognition of this problem suggests a possible solution that during the closing operation the sides of the bag be restrained in such a manner that the bag assumes the rectangularly prismatic shape from which a perfect closure fold can be made. However, after the bag is closed and after it is no longer rest-rained in this prismatic shape, with only moderate jostling in the subsequent handling of the bag, the product settles in the bag to bulge out the sides thereof and the product level drops away from closure portion of the bag. With the resulting loose pack of the product, the top of the bag easily becomes crushed down, and the appearance of the bag, when it does reach the final consumer, is less than wholly desirable. Also, if the product is such that it is easily blown by air currents, the air pocket which forms at the top of the bag can be a source of sifting. That is to say, pressure applied to the top of the bag will cause air turbulence in the void or air pocket in the top of the bag, and the product can be blown out through small passages which are sometimes present inthe. closure portion of the bag.

The practical approaches to this dilemma have varied. One is simply to permit the product to bulge the sides of the bag outwardly and make a loose closure at the top of the bag (i.e. the closure assuming a tent-like configuration), which closure may be crushed down in subsequent handling. Another has been to make a tight pack and accept the fact that there will be wrinkles formed in the same. Also different types of closures have been attempted, with varying degrees of success. There are, of course, many other problems which arise when it is attempted to close the bags mechanically in a commercial "operation. Among these are properly orienting the bag in the machine, handling the filled bags in such a way as not to disturb the level of the product in the bag, and many other problems relating to the mechanics of engaging the bag, folding the same, etc.

In the present invention, filled bags are received at random spacing and are fed or indexed into pockets on a continuously, moving chain. The top portion of each bag is squared up to some extent in its pocket, and as each bag is carried through a folding zone, it is carefully folded in (by a mechanism to be described with some particularity hereinafter) in a manner that wrinkling of the bag is obviated to a large extent and yet the bag is closed in such a way that a reasonably tight pack of the product is achieved. While the bag is still in the machine, it can very conveniently be sewn, taped, glued and/or folded over, and then be discharged from the machine.

Continuing now to a detailed description of the present invention, a view of the entire machine is presented in side elevation when FIGURES 2A and 2B are placed side by side. As shown herein, the construction of the machine is such that its length is considerably greater than its width, with the open bags entering at one end of the machine and being discharged at the opposite end thereof. To establish a basis for orienting the various components in the following description, the longitudinal axis of the machine will be considered as coincident with the lengthwise dimension of the machine; the progression of the bags in the machine will be considered as being forward so that the infeed end of the machine is the rear end and the outfeed end the front end; and right and left will be oriented with respect to a person at the rear of the machine looking to the front end thereof. The terms clockwise and counter-clockwise will be taken from a reference location above the machine looking down toward the same, and inward and outward, as used in describing the folding operation, will denote proximity to the vertical center axis of each bag being folded.

As illustrated in FIGURES 2A and 2B, the entire apparatus is mounted from a base frame 18, the lower portion of which carries the various drives for the apparatus (to be described in the latter part of this description) and the upper portion of which carries the working components of the machine. For purposes of description, the working components of the present invention can be considered as making up four parts of the machine: (a) an infeed portion 20 which receives open filled bags 14? at random intervals and indexes them into the machine, (b) a conveying mechanism 22 which receives the bags 10 from the infeed portion and moves the same from the rear to the front end of the machine, (c) a fold-in mechanism 24 located above conveying mechanism and between the ends thereof, which fold-in mechanism 24 cooperates with the convey-ing mechanism to fold the closure portions 10' of the filled bags 10, and (d) a discharge mechanism 26 located at the front of the machine, which mechanism, as its name implies, moves the bags 10 from the machine.

The infeed portion 20 (best illustrated in FIGURE 4) comprises a first longitudinally aligned belt conveyor 28 which functions to receive filled bags 10 at random intervals and carries each to a preload station at the forward end of the belt 28. This'belt 28 trains over front and rear rollers 30 and 32, respectively, which are in turn journal mounted to the base frame 18, with the rear roller 32 being provided with a longitudinally adjustable screw device'34 so that proper tension may be maintained on the belt 28. A vertical, transversely aligned stop plate 36 is positioned above the belt 28 at the forward end thereof to detain each bag 10 on the forward end of the belt 28 at a location which can be termed a pre-load station, at which a bag 10 is shown situated in FIGURE 4. (The belt 28 is moving continuously and merely slides beneath the bag 10 as it is held by the plate 36 at the preload station.) A pair of resilient fingers 38 and 40 are provided to engage the upper portion of each bag 10 on the front and rear sides thereof to prevent the bag from toppling over when it is moved laterally from the pre-load station to a loading station. Also, it will be noted that there is a contact switch 42 located at this pre-load station. This switch 42 is closed by the bag 10 moving into the preload station, and (as will be described more fully hereinafter) functions to cooperate with other components of a timing or interlock mechanism to move the bags 10 through the infeed mechanism and into the conveying mechanism 22 at properly timed intervals.

Located to the left (as seen in FIGURE 4) of the preload station, is a preload pushing mechanism, generally designated 44, which functions to move each bag 10 from the preload station to a loading station from which the bag 10 is indexed or fed into the conveying mechanism 22. This preload pusher 44 comprises a transversely and horizontally aligned push bar 46 swing mounted by a parallel linkage 48 pivotly secured at 50 by the lower end thereof about a longitudinally aligned axes to the base frame 18. An air cylinder and piston unit 52 is connected by one end at 54 to the parallel linkage 48 and by the other end (this connection not being illustrated) to the base frame 18 so as to be able to cause the push bar 46 to move transversely and push a bag 10 from the preload station to the loading station and then retract the bar 46 to its original position.

The bag 10, at its loading station, rests upon a stationary horizontai platform 58 (i.e., a loading platform), from which an indexing or loading push mechanism, generally designated 60, moves each bag 10 forwardly into the conveying mechanism 22. This push mechanism 60 is, in its structure and operation, similar to the preload push mechanism 44, although oriented at right angles with respect thereto. Accordingly, the mechanism 60 comprises a push bar 62 mounted from a parallel linkage 64, which in turn is pivotally mounted at 66 to the base frame 18 and is actuated by an air cylinder and piston unit 68 connected between the linkage 64 and the base frame 18.

Immediately forward of the loading platform 58 and coplanar therewith is a longitudinally disposed forwardly traveling conveyor belt 70, which, in cooperation with the indexing push mechanism 60, functions to load each bag 10 into the conveying mechanism 22. This belt 70 trains over a front live roller 72 driven by a shaft 74, and over a rear roller 76, which for convenience is rotatably mounted on a shaft 78 which is fixedly secured to, and serves the additional function of a drive shaft for, the drive roller of the belt 28. So that slack may be taken up in the belt 70, the right end of the drive shaft 78 is journal mounted from a longitudinally adjustable bracket 80.

A right and a left guide rail 82 and 84, respectively, are provided for the bags 10, which guide rails 82 and 84 extend forwardly from the loading platform 58 along substantially the entire length of the conveying mechanism 22. While the rear end of the left guide rail 84 begins just forward of the loading platform 58, the rear end of the right guide rail 82 extends further rearward to serve the function of a stop plate for each bag 10 as it is pushed by the preload mechanism 44 to the loading station. A second contact switch 86 is mounted at the loading station in a manner that it is closed by each bag 10 being moved by the preload mechanism 44 into the loading station. This switch 86 serves a similar function to the switch 42 in that it cooperates with other components of an interlock mechanism (to be described hereinafter) to properly index the bags 10 in the conveying mechanism 22.

The conveying mechanism 22 comprises a conventional endless chain table top conveyor, generally designated 88, on which are mounted at evenly spaced intervals a plurality of units 90 (called pocket assembly units) which serve not only to move the bags 10 through the 'machine, but, as will be disclosed more fully hereinafter, 'also cooperate with the fold-in mechanism 24 in folding 6 the bags 10. (For clarity of illustration only one such unit 90 is shown in FIGURE 2.) This conveyor 88 comprises an endless chain 92 made up of a plurality of links 94, each of which has a general plate-like configuration, and the chain 92 trains around front and rear sprockets 96 and 98, respectively. The entire table top conveyor 88 is turned on its side so that the sprockets 96 and 98 each rotate about a respective vertical axis and the chain 92 travels a completely horizontal path (which, as seen in top plan view, is counterclockwise), with the plane of each link 94 being at all times vertically disposed. The right and left run (i.e. forward and rear run, respectively) of the chain 92 are each provided with an upper and a lower guideway 100 and 102 which engage, respectively, the upper and lower edge of each plate link 94 passing therethrough so as to support the same and maintain the proper alignment thereof. So that the chain 92 can be kept taut, the rear sprocket 98 is provided with a suitable screw adjustment device such as that indicated at 104.

Each adjacent pair of pocket assemblies 90 define therebetween a pocket into which the infeed mechanism 20 indexes a bag 10 (the manner in which this is accomplished being best illustrated in FIGURE 4), and each such assembly or unit 90 also performs a folding function in cooperation with the fold-in mechanism 24 (this function being best illustrated in FIGURE 6, wherein a pair of such units 90 is shown moving a bag 10 through the folding station of the apparatus of the present invention). Each unit 90 comprises a forward and rearward plate 106 and 108, respectively, both of which are fixedly secured to a related mounting plate 110, which is in turn bolted, as at 112, to a related plate link 94 of the chain 92. The plates 106 and 108 are vertically aligned and extend outwardly from, and at right angles to, their related plate link 94, with the result that the rearward plate 108 of one unit 90 cooperates with the forward plate 106 of the next rearward unit 90 to become, respectively, front and rear transverse walls of a related pocket to accommodate a bag 10.

The manner in which each bag 10 is indexed into a related pocket is best explained with reference to FIGURE 4, wherein one pocket assembly unit 90 is shown beginning a path of travel along the forward run of the chain 92, and a following unit 90 is shown traveling a semi-circular path about the periphery of the rear sprocket 98. With these two units 90 so angled with respect to one another, the pocket defined therebetween is expanded to an open position. The aforementioned loading pusher bar 62 and the loading conveyor 70 are in alignment with the forward path of travel of the pocket assembly units 90, and the front end of the conveyor 70 extends forward a moderate distance beneath the rear portion of the for ward path of travel of the pocket assembly units 90. The infeed timing mechanism (to be described later herein) is so arranged that a bag 10 is moved by the loading pusher mechanism from the loading station forwardly against the rearward plate 108 of the unit 90 which is just beginning its forward path of travel. The conveyor moves at a rate slightly faster (e.g. 20% faster) than the linear speed of the chain 92. Consequently, after the loading push bar 62 moves a bag 10 against the rearward plate 108 of the unit 90, the conveyor continues to move the bag 10 forward so that the bag 10 maintains contact with the plate 108 (the conveyor belt 70 will slide beneath the bag to some extent because of the somewhat greater speed of the belt 70 relative to the chain 92), until the succeeding pocket assembly unit has completed its arcuate path of travel about the periphery of the rear sprocket 98 and engages the rear of the bag 10 with its forward plate 106. At this stage, the pocket is closed, with a bag 10 held snugly between the two units 90, which then carry this bag 10 through the fold-in station and thence to the discharge end of the machine.

To consider now the components by which the bags 10 are folded in, there are pivotally mounted about a respective transverse horizontal axis at the top edge of, respectively, the plates 106 and ltls, two delta-shaped plates 114 and 116 (called gusset plates), which func-.

tion to fold in the closure portions 14 of the end walls 14 of a related bag 10. Each gusset plate 114 or 116 has the general configuration of a right isosceles triangle and is hinge mounted, as at 118, by its hypotenuse side about an axis closely adjacent to the proximate bag end panel 14 and at about the same elevation as the product level 16 in the bag 10. The triangular configuration of each gusset plate 114 or 116 is such as to be generally congruent with a related one of the two triangular portions b, e, c (see FIGURE 13) of the bag closure portion 14', and each gusset plate 114 or 116 is so positioned that during the folding operation it is adjacent to, and coincides with, its related triangular bag portion b, e, c, which, as will be disclosed hereinafter, it folds in and down. As shown herein, this is conveniently accomplished by locating the axis of the hinge 118 slightly above the product level 16' of the bag 10, and fixing the related gusset plate 114 or 116 so that in its upstanding position, it is tangent to such hinge 118 along a tangent line proximate the bag 10 which it is folding.

Each gusset plate 114 or 116 is urged to an upstanding position by means of a related tension spring 120 which is secured by one end to its related gusset plate 114 or 116 and by the other end (by means of an adjustable screw 122 so that the tension on the spring 120 can be adjusted) to a bracing plate 124 at the lower end of the unit 510. To cause each pair of gusset plates 114 and 116 which are adjacent to a pocket to move inwardly and downwardly in unison in a predetermined manner so as to accomplish their intended folding function, there is provided a pair of cams 126 and 128 to engage respective cam followers 130 and 132 of gusset plates 114 and 116. The manner in which the cams 126 and 128 move the gusset plates 116 and 114 is best illustrated in FIGURES 9, 10 and 11 which disclose the cam surfaces of cams 126 and 128 as each being made up of for parts, designated 126a, b, c and d, and 128a, b, c and d, respectively. The gusset plates 114 and 116 are normally upright, although for purposes of illustration, when shown in plain view, they are shown as slanting to a moderate degree. The a cam surface portion of each of the cams 126 and 123 serves to move the related gusset plates 114 or 116 from an upright position slightly inward (i.e. about 15 from the vertical) so as to push in the related end closure portions 14' inwardly to a moderate extent, and the gusset plates, '114 and 116 remain at this position as the cams 130 or 132 move along the b sections of their respective cam surfaces 126 and 128 (as shown in FIGURE 10). The portions of the cam surfaces next engage the cam followers 130 and 132 to move the gusset plate 114 and 116 down to 'a near horizontal position, with the a portion of the cam sur-' faces then functioning to hold each gusset plate 114 or 116 in this hold-down near horizontal position (as shown in FIGURE 11).

The fold-in mechanism 24 of the present invention (best illustrated in FIGURES through 8) functions to move a pair of vertically and longitudinally aligned parallel fold-in plates 134 inwardly and forwardly in timed relation with the travel of the bags and with the movement of the aforedescribed gusset plates 114 and 116 to fold in the side panel closure portions 12 of each bag 10. To accomplish this fold-in motion, each plate 134 is carried by a related pair of horizontally disposed, parallel mounting arms 136, each of which is fixed by its root end to a respective vertical shaft 138, and is pivotally connected by its outer end, as at 141), to a mounting piece 142 bolted to a flange formed integrally with its related fold-in plate 134. The two drive shafts 133 for the right hand fold-in plate 134 rotate clockwise, while the other two shafts 138 for the left hand fold-in plate 134 rotate counter-clockwise, with the result that the '8 two plates 134, while maintaining their parallel relationship, follow counter rotating circular paths which come nearly tangent to one another along a plane coinciding with the longitudinal center line of the forward path of travel of the bags 19, this being shown in FIGURES 5 and 8.

This fold-in mechanism 24 is mounted from an overhead frame 144 which contains a drive mechanism to rotate the shafts 138 of the fold-in plates 134 in the aforedescribed manner. As illustrated in FIGURE 5, a main drive shaft 146 for the fold-in mechanism 24 reaches upwardly into the frame 144 and is fixed to a main drive gear 148 which in turn engages a second gear 1513 fixed to one of the drive shafts 138. Each of the shafts 138 has fixed thereto a respective one of four sprockets 152, and the two sprockets 152 of the right hand shafts 138 are interconnected by a chain 154, as are the two gears 152 of the left hand shaft 138. As shown in FIGURE 7, (the two left hand shafts 138 are driven in a counterclockwise direction through the gear 150. To cause the two right hand shafts 138 to rotate in an opposite direction, a chain and sprocket drive 155 driven from a left hand shaft 138 turns an intermediate shaft 156 on which is fixedly mounted a gear 158 meshing with another gear 160 fixed to one of the right hand drive shafts 138. Suitable idler sprockets 162 are provided to place the proper tension on the various chain drives.

To provide vertical support for the bags It? as each is carried by the chain conveyor 88, there is a longitudinally aligned horizontal platform 164 over which the bags 10 slide between a pair of longitudinal guideways 166 and 168, fixed to or integral with, and upstanding a short distance from, the platform 164. To minimize any wrinkling in the closing of the bag 10, it is important not only that the bag 10 be carefully located with respect to the components which fold the same, but that the portion of the bag just below the product level 16 be squared up to some extent (this being best understood with reference to FIGURES 5 and 6). Thus, each bag is restrained by the rails 82 and 84 and by the walls 108 and 1116 of, respectively, the pocket assembly units 90 located in front of and behind the bag 10. The guide rails 82 and 84 are so disposed that the upper edge of each is at, or just below, the product level 16' of the bag 10, with the lower edge of the rails 82 and 84 being moderately above the midheight of the bag 10. In like manner, the upper portions 106 and 108' of, respectively, the pocket assembly walls 106 and 108 are joggled inwardly to a moderate degree at about the same height as the lower edges of the rails 82 and 84. The effect is that the upper portion of each bag 10 below the closure portion 10' thereof is restrained or pushed in on all four sides so as to assume a somewhat rectangular configuration, while the middle and lower portions of the bag 10 are permitted to bulge outwardly. The bag engaging surfaces of the rails 32 and 84 are desirably faced with a low friction material so that these rails 82 and 84 can exert adequate pressure against the bag 10 and yet permit the same to slide between the rails 32 and 84.

Immediately forward of the fold-in station (i.e. the location at which the fold-in plates 134 and gusset plates 114 and 116 cooperate to collapse the closure portion 10 of each bag 10) there is a pair of longitudinally extending hold-down arms 170. These arms 170 are horizontally disposed so as to occupy a single plane just above the product level 16 of each of the bags 10 traveling through the conveying mechanism 24, and are spaced laterally to a moderate degree so as to define therebetween a somewhat narrow longitudinal slot (as shown in FIGURE 5) to accommodate the extreme upper end portion of each bag 10 which portion remains upstanding after the bag '10 has passed through the fold-in station. The rear end portion 172 of each of the arms 170 has a moderate upward and outward bend (in a general plow share configuration) so that as each bag travels forwardly from the fold-in station, the two rectangular portions a, b, 1, g of the side panel closure portions 12' (see FIGURE 1B) are engaged by these rear arm portions 172 and pressed downwardly against the product level 16' of the bags 10.

With the bags closure portion 10' being so held by the arms 170 (as shown in FIGURE 5) and with the bag being moved by the conveying mechanism 22 to the discharge end of the machine, other closure operations can conveniently be performed. Thus the top edge of the bag 10 can be cut off, the bag sewn, and possibly glued and folded down to the configuration shown in FIGURE 1D. Since various devices which are able to perform such further closure operations are well known in the art, it is believed not to be necessary for a full understanding of the present invention, to describe such devices in any detail. Accordingly, it is believed to be enough to indicate that devices such as a bag cutting and stitching apparatus and a glue applicator could be mounted on the machine at locations above the conveying mechanism 22.

and forward of the fold-in mechanism 24.

The operation of the discharge mechanism 26 will be best understood with reference to FIGURES 2B, 12A and 12B. It will be noted that when each bag 10 is closed at the folding station, the gusset plates 114 and 116 reach into the closure portion 10' of the bag 10, with each gusset plate 114 or 116 overlying a related bag triangular portion b, c, e, and with the other related triangular portions e, f, b and e, d, c and the proximate end portions of the rectangles a, b, g overlying the guseet plates 114 or 116. As each bag 10 moves from the fold-in station, the aforementioned cam surface portions 126d and 128d hold the gusset plates 114 and 116 down until the hold down arms 170 are able to press down against the rectangular bag portions a, b, j, g and hold the bag closure portion 10' and the guseet plates 114 and 116 in this down position. In most bag closing operations where the present invention is used, each bag 10, while it is held by the arms 170, will be closed so that the rectangular portions a, b, g of the side panel closure portions 12' are in somewhat closed proximity to the product level 16' of the bag 10, for example, as shown in FIGURE 1D. The result is that when each bag 10 moves forward in the machine to the extent that it is free of the holddown arms 170, the gusset plates 114 and 116, although urged upwardly with moderate force by the tension springs 120, will not be able to spring up free of the bag closure portion 10.

To accomplish the discharge of the bags 10 from the machine in a manner that the gusset plates 114 and 116 are removed from the bag closure portion 10', there is provided a conveyor belt 174 which trains over front and rear rollers 176 and 178, respectively, with the front roller 176 having a longitudinally adjustable mounting 180 so that the belt 174 may be kept reasonably taut.

The forward upper run of the belt 174 is located immedi-' ately in front of the bag supporting platform 164 and is longitudinally aligned and coplanar therewith. As a pair of pocket assembly units 90 carry a bag to the front end of the conveying mechanism 22, the bag 10 slides from the stationary platform 164 onto the belt 174 which moves at a rate moderately faster (eg, 20% faster) than the linear rate of travel of the chain 92 of the conveyor 88. As the unit 90 in front of the bag 10 begins to travel in an arcuate path about the front sprocket 96 of the conveyor 88, its rearwardly extending gusset plate 116 slips out of the closure portion 10' of the bag 10 (as illustrated in FIGURE 12B). Also, the front pocketdefining plate 168 swings away from the bag 10 with the result that the conveyor belt 174, moving moderately faster than the units 90 mounted on the chain 92, carries the bag 10 forwardly away from the rear pocket-defining plate 106 (as illustrated in FIGURE 12A) of the succeeding unit 90, so that the bag 10 moves free of the gusset plate 114. Each bag 10 can then be carried from the belt 174 either manually or by some other apparatus.

As indicated previously, the drive mechanism for the present invention is mounted in the lower portion of the base frame 18. Power is supplied to the machine from a motor 182 which through a chain and sprocket drive 184 and a speed reducing gear box 186 turns a vertically aligned main drive shaft 183. Two chain and sprocket drives 190 and 192 are powered from the shaft 188 and extend, respectively, forwardly and rearwardly therefrom. The forward chain and sprocket drive 190 rotates a vertical shaft 194 which through a splined connection 196 powers another shaft 198 (which is, in effect, an upward extension of the shaft 194), which shaft 198 drives the front sprocket 96 of the chain conveyor 88. (As will be disclosed more fully hereinafter, the splined connection 196 permits the shaft unit 194498 to be elongated or shortened when the machine is adjusted vertically.) The shaft 194 through another chain and sprocket .drive 200, a right angle gear box 202 and a second chain and sprocket drive 264 rotates the front roller 176 of the discharge belt 17 4.

The aforementioned chain and sprocket drive 192 which extends rearwardly from the main drive shaft 188, turns a transversely horizontally aligned shaft 266 through a right angle gear box 208. The two conveyor belts 28, and 70 of the infeed mechanism 26 are driven from this drive shaft 266 through chain and sprocket drives 210 and 212, respectively. It will be noted, as illustrated in FIGURE 3A, that a chain and sprocket drive 214 is also driven from the gear box 208 to turn a shaft 216 on which are mounted four cam members, designated 218, 220, 222 and 224. As will be disclosed more fully hereinafter, these cam members are part of an interlock mechanism which cooperates with the infeed mechanism 20 so that the bags 10 are properly indexed in the conveying mechanism 22.

As indicated previously, the machine of the present invention receives bags 10 which have been filled to a predetermined product level 16'. In the event that it is desired to fill the bags 10 to a different level, the machine is provided with a vertical adjustment feature to permit the machine to be adapted to this change in the bag product level. This feature is best illustrated by referring to FIGURES 5, l3 and 14, the latter two figures being stripped down views to better expose the manner in which certain of the components of the present invention are made vertically adjustable.

Located below and aligned with the chain conveyor 88 is a longitudinally extending secondary frame 226 which is vertically supported by front and rear screw jacks 228 and 2313, respectively. These jacks 228 and 230 are driven in unison from a single transmission unit 232 (powered manually by means of a handle 234) through respective longitudinal drive shafts 236 and 238. To maintain the horizontal alignment of the secondary frame 226 there is bolted thereto a front and rear pair of vertically aligned guide sleeves 240, each of which slidably engages a respective vertically aligned post 242 fixedly mounted to the base frame 18. 2

As a rough generalization, it may be said that the infeed mechanism 20 and outfeed mechanism 26 are mounted directly to the base frame 18, so as to remain at a constant elevation with respect thereto, while the conveying mechanism 22 and the fold-in mechanism 24 are both mounted directly to the secondary frame 226 so as to be vertically movable therewith. Thus, the mounting frame 144 of the fold-in mechanism 24 is bolted, as at 244, to the secondary frame 226, as are the aforementioned chain conveyor guideways and 102, the left guide rail 84, the holddown plates 170, and the adjustment device 104 for the rear sprocket 98 of the conveying mechanism 22. The aforementioned drive shaft 198 for the front drive sprocket 96 of the conveying mechanism 22 is mounted to the secondary frame 226 through upper and lower thrust and journal bearings 246 and 248, respectively, and the rear sprocket 98 is similarly mounted through a shaft 250 to upper and lower bearings 252 and 254 in the frame 226.

The drive assembly for the fold-in mechanism 24 is powered from the front drive sprocket 96 of the conveying mechanism 22, and is carried by the vertically adjustable secondary frame 226. This drive comprises a chain and sprocket unit 256 driven from the shaft 198 and operatively connected to a longitudinal drive shaft 258 through a right angle gear box 26%. This shaft 258 in turn powers the aforementioned main drive shaft 146 for the fold-in mechanism 24 by means of a second right angle. gear box 262.

When it is desired to close bags having a product level 16 higher or lower than the level for which the machine is set, the jacks 228 and 23%) are raised or lowered accordingly by means of the handle 234. F or practical reasons relating to the particular arrangement of the various components of the machine, the right hand guide rail 82 is not mounted to the vertically adjustable secondary frame 226 but is mounted from the base frame 18 by a vertically adjustable screw mounting 82a, which must be manually adjusted in addition to raising or lowering the jacks 228 and 230.

As indicated previously, the preload pusher 44 and the loading pusher 60 operate in timed relationship with the conveying mechanism 22 to properly index each bag into a related one of the pockets defined by the units 91) carried by the chain conveyor 88. The control or interlock mechanism by which this is accomplished is best disclosed with reference to FIGURE 15, wherein the same is shown schematically. The cylinder and piston unit 52 for the preload pusher 44 is controlled through a fourway valve 270, which in its right hand position holds pistons 52a of the unit 52 in its extended position, and in its left hand position (as it is in FIGURE retracts the unit 52 to push a bag 10 from the preload station to the loading station. To control the action of the four-way valve 270, there'are provided three switches, one being the aforementioned preload contact switch 42, and the other two, designated 272 and 274, being operated, respectively, from cams 218 and 220. Each of these three switches 42, 272 and 274 is urged to its off position by a spring 276 contained therein. The switches 42 and 274- are connected in series between the air supply and the valve 27%), in a manner that when both switches 42 and 274 are closed (so as to permit air to pass therethrough), the four-way valve 2-70 is urged to its left position where it contracts the unit 52 so that the pusher 44 moves a bag 10 from the preload station to the loading station. When the other valve 272 is opened, it feeds air from the air supply to the four-way valve 270 in a manner that the valve 270 is urged to its right hand position so as to extend the cylinder and piston unit 52 so as to retract the preload pusher 44 and permit another bag 10 to be moved into the preload station.

As illustrated in FIGURE 15, the interlock control for the cylinder and piston unit 68 for the loading pusher is substantially identical to that of the cylinder and piston unit 52 for the preload pusher 44, and accordingly components associated with the loading pusher 6!) which have not previously been given numerical designations will be given the same numerical designations as corresponding compenents associated with the preload pusher 44, with a prime designation distinguishing those associated with the loading pusher 60. Thus the cylinder and piston unit is operated through a four way control valve 270', which is in turn controlled by the aforementioned contact switch 86 and two other switches 272 and 274', with the latter two switches 272' and 274 being operated by cams 222 and 224, respectively. The lines which lead to the air cylinder and piston units 52 and ddare each provided with a valve unit 273 which permits free flow into its related cylinder and controlled variable flow from the cylinder, so that the speed with which the units 52 and 63 act can be controlled.

With there being a positive drive from the main drive shaft 1&8 to both the chain conveyor 88 and the cams 213- 224, the action of the cams 213-224 is in timed relationship with the movement of the conveying mechanism 22 in a manner that the cams 218-224- are caused to go through one cycle of revolution as the chain conveyor moves an increment of distance equal to the spacing between the pocket assembly units 9 9. To follow the interlock mechanism through a sequence of operation, initially the four-way valves 27% and 270 are each in its right-hand position so that the cylinder and piston units 52 and 68 are extended. When a bag 10 is carried by the preload conveyor 28 to the preload station, this bag 10 presses the switch 42 to its closed position. The bag 10 remains at this preload station until the cam 220 engages the switch 274 to close the same, this causing a pulse of air to travel into the right side of valve 270 to move the same to its left-hand position and contract the cylinder and piston unit 52. This causes the push bar 46 to move the bag 10 from its preload station to the loading station, permitting the switch 42 to spring back to its off position. At the same time the cam 220 has rotated through a short increment of travel to permit the switch 274 to move to its off position. Immediately after this, the cam 218 closes the switch 272, and a pulse of air moves into the left side of the valve 270 to move the same to its right-hand position so that the unit 52 becomes extended to retract the push bar 46 so that a second bag It may be moved into the preload station.

The manner in which the components of the interlock mechanism which are associated with the cylinder and piston unit 68 operate to push the bag 10 into the conveying mechanism 22 is substantially the same as that described in the immediately preceeding paragraph. Movement of the bag 10 into the loading station closes the contact switch 84, and when the cam 224 moves the valve 274 to its closed position, the four-way valve 270' is moved to its left-hand position to contract the cylinder and piston unit 68 and cause the push bar 62 to move the bag 10 from the loading station into an open pocket defined by a pair of pocket'assembly units 90 (as shown in FIGURE 4). Immediately after this, the valve 272' is engaged by the cam222 to extend the unit 68 and retract the bar 62. Thus it can be seen that the preload pusher 44 and the loading pusher 60 will operate only when a bag is at respectively, the preload station and the loading station, and then only in timed relationship with the conveying mechanism 22 as determined by the action of the cams 218, 220, 222 and 224.

To describe now the overall operation of the present invention, the machine receives open bags 10, each of which has been filled with the product 16 to a predetermined level 16', these bags 14) being fed onto the preload conveyor belt 28 at random intervals. The conveyor belt 28 carries each bag 10 to the preload station, and the bag 10 remains at the station until the pocket assembly units 90 on the chain conveyor 88 of the conveying mechanism 22 have reached a predetermined location so that the associated cam 22% (which makes one revolution each time the chain conveyor moves through an increment of travel equal to the spacing of the units 20) initiates the timed loading or indexing of the bags 10 from the preload station to the loading station and into the. conveying mechanism 22. As previously described, the preload pusher 44 pushes the bag 10 from the preload station to the loading station and then (by the action of the cam 218) immediately retracts so that a second bag It can be fed into the preload station. Next, the indexing or loading pusher 6t) (activated by the cam 224) moves the bag lltl from the loading station onto the loading conveyor and against the rearward plate 108 of a pocket assembly unit 9% which is just beginning its forward path of travel through the machine. Immediately after so moving the bag 10 into the conveying mechanism, the indexing pusher 6t retracts (by the action of the cam 

1. A MACHINE TO CLOSE FILLED BAGS, EACH OF WHICH HAS TWO SIDE PANELS AND TWO END PANELS, EACH OF THE UPPER PORTIONS OF SAID SIDE AND END PANELS BEING A RESPECTIVE CLOSURE PORTION THEREOF, SAID MACHINE BEING ARRANGED TO CLOSE EACH BAG IN A MANNER THAT EACH END PANEL CLOSURE PORTION HAS A LOWER TRIANGULAR PART THEREOF TUCKED IN AND DOWN SO THAT AN UPPER PART THEREOF IS FORMED WITH A VERTICAL REENTRANT FOLD, AND THE SIDE PANEL CLOSURE PORTIONS ARE MOVED INWARDLY SO THAT LOWER PARTS THEREOF ARE FOLDED IN AND DOWN, AND UPPER PARTS THEREOF ARE MOVED AGAINST ONE ANOTHER SO AS TO ENCLOSE THEREBETWEEN SAID UPPER END PANEL CLOSURE PARTS, SAID MACHINE COMPRISING: (A) CHAIN CONVEYOR MEANS WHICH TRAVEL IN A CONTINUOUS MANNER A PREDETERMINED COURSE FROM AN INFEED STATION FORWARDLY THROUGH A FOLDING STATION TO A DISCHARGE STATION; (B) A PLURALITY OF POCKET FORMING MEMBERS SECURED TO SAID CHAIN CONVEYOR MEANS, PROXIMATE PAIRS OF SAID POCKET FORMING MEMBERS DEFINING THEREBETWEEN RESPECTIVE BAG ENGAGING POCKETS; (C) SPROCKET MEANS AT SAID INFEED STATION TO DIRECT SAID CHAIN CONVEYOR MEANS IN A CURVED PATH, WHEREBY PROXIMATE PAIRS OF POCKET FORMING MEMBERS ARE SPREAD ANGULARLY WITH RESPECT TO ONE ANOTHER AS THEY TRAVEL SAID CURVED PATH TO DEFINE SPREAD POCKETS; (D) INFEED MEANS TO MOVE FILLED BAGS INTO SAID SPREAD POCKETS AT SAID INFEED STATION; (E) FOLDING MEANS TO ENGAGE EACH BAG AT SAID FOLDING STATION, SAID FOLDING MEANS COMPRISING SIDE CLOSURE MEMBERS TO ENGAGE THE SIDE PANEL CLOSURE PORTIONS, AND END CLOSURE MEMBERS TO ENGAGE SAID END PANEL CLOSURE PORTIONS AT THE LOWER TRIANGULAR PARTS THEREOF OF FOLD SAID LOWER TRIANGULAR PARTS INWARDLY AND DOWN; (F) SAID SIDE CLOSURE MEMBERS BEING MOVABLE INWARDLY AND FORWARDLY TO ENGAGE AND MOVE WITH SAID SIDE PANELS AT SAID FOLDING STATION, AND (G) SAID END CLOSURE MEMBERS BEING MOVABLE WITH SAID CHAIN CONVEYOR MEANS SO AS TO MOVE WITH SAID BAGS WHILE PERFORMING THEIR FOLDING FUNCTION. 